Authentication of processes or services running on unattended computer-based systems has always been a thorny problem. Having a user authenticate every time processes are started is extremely inconvenient. The alternative is to leave passwords or credentials on the machine and automate logins. That has problems if the machines are compromised as even with technologies like TCPA or smartcards, the authentication tokens are still available on the machine allowing access to anything the uncompromised machine had access to. Unattended processes run in many server farms in the world. Having a human administrator present every time the subject machine or process has to be restarted is not feasible.